He cheated on me with my cousin

I've been separated from the, then, love of my life for almost 2 years now. I was with him for nearly 17 years. Over the past couple of years, we've stayed friends while we try and repair ourselves as individuals. It's not been easy but I thought it was going ok until recently.

A bit of history; Back in 2021-22 he cheated on me with my cousin on multiple occasions while I was at work. They both even snuck around behind my back to go to the health department to get STD tested after it happened....